ON/OFF tube weights are being in use since years along with the drip irrigation tubes to irrigate plants grown in basket or at the initial nursery stage. The plants need to be provided with required amount of water and fertilizers at regular interval for healthy growth. In plant nursery, the plants are kept for some pre-estimated period under controlled conditions and then these plants are shifted to the field or other place. In order to irrigate these plants at nursery stage, modern nursery uses drip irrigation system to irrigate these plants. Depending on the growth and maturity achieved, these plants are shifted out periodically. Thus it is not necessary that all the plants at the nursery shed are shifted out at once. As plants are shifted out depending on their level of maturity, the pre-installed drip system cannot be shut off pursuant to shifting the mature plants, as this may result in unhealthy growth of remaining plants. So there is a need for a system, which allows shutting off the water and nutrient supply of individual plant without affecting the other plants. This is achieved by the use of ON/OFF tube weights.
One such ON/OFF tube weight presently known, is made of lead material. The complete component is an assembly of three components along with an additional operation of flaring. The tube is inserted and flared inside the assembly to get some pulling strength. Below this flared tube one conical needle arrangement is placed. In order to stop the water and fertilizer discharge, one needs to push fit the tube over the conical needle. This assembly stops the discharge. However, this system has certain drawbacks such as the complete assembly is a factory fitted assembly, thus failure of one component results in replacement of the complete assembly. Change in discharge of the tube weight, by changing the tube only is not possible, because the shut off is based on push fit principle without backing. Further, for elastic material, the tube weight results in partial shut off over a period of time. Apart from above drawbacks, the body is made of lead material, which is not environmental friendly.
Another tube weight presently known is made of plastic and metal part. This ON/OFF tube weight is provided with a female slot on its surface. To close the discharge, the tube needs to be bent by 180 degrees and inserted into this female slot. The drawbacks of this system are that the tube needs to be bent by 180 degrees. Frequent bending of the tube results in reduced tube life and also the tube needs to be bent sharp at 180 degrees. Slight negligence in it may result in partial shut off